In Boros legend decks, owyn can clear the path for a massive, protected attack that puts the game firmly in your favor
Mystic RemoraMystic Remora (Skullclamp: 612,847 Inclusions, Sentinel: 459,136, Remora: 436,757) And
Dreamstone Hedron One of several mana rocks that draw you 2+ cards, Dreamstone Hedron provides a ramp effect when needed and can be ditched for more cards when it's no longer useful
The most common way for this deck to win is by amassing a huge board of Moogle tokens, then alpha-striking with support from cards like Moonshaker CavalryMoonshaker Cavalry, Elspeth, Storm SlayerElspeth, Storm Slayer, or Serra's EmissarySerra's Emissary to get around blockers
Cards like Scute Swarm or Rabble Rousing can put so many creatures on board that your opponents won't be able to defend against a giant Devilish Valet